1. Technical Field
The present invention relates to a head repairing apparatus for repairing a liquid ejecting head of a liquid ejecting apparatus which ejects liquid from a liquid ejecting nozzle provided on a head surface of the liquid ejecting head to an ejection object.
2. Related Art
In a known ink jet printer as an example of a liquid ejecting apparatus, in order to always maintain a head surface of a recording head (a liquid ejecting head) in a favorable state, there is generally provided a head repairing apparatus for repairing the recording head between standby and recording implementation. As one of main functions of the head repairing apparatus, there is a function that seals the head surface of the recording head with a seal member during standby to prevent ink of an ink ejecting nozzle provided at the head surface from drying, thereby preventing a nozzle blockage or the like. Specifically, there is provided a mechanism which brings the seal member in close contact with the head surface of the recording head during standby to seal the head surface and separates the seal member from the head surface of the recording head during recording implementation.
In addition, as one of the main functions of the head repairing apparatus, there is a function that, in a state of sealing the head surface of the recording head with the seal member, generates a negative pressure at a closed space formed between the head surface of the recording head and the sealing surface of the seal member, thereby sucking the ink within the ink ejecting nozzle by the negative pressure. Specifically, there are provided a suction path that communicates with the sealing surface of the seal member, a pump capable of sucking the suction path, an atmosphere communication path that causes the sealing surface of the seal member to communicate with the atmosphere, a valve mechanism for opening and closing the atmosphere communication path or the like (see, for example, JP-A-2005-66852).
In the head repairing apparatus of this configuration, two types of suction motions can be performed according to objects. Two types of suction motions as described below can be selected by performing the suction motion in the state in which the atmosphere communication path is opened or performing the suction motion in the state in which the atmosphere communication path is closed.
One of them is a suction motion that seals the head surface of the recording head with the sealing surface of the seal member and operates the suction pump in the state of closing the atmosphere communication path (hereinafter, referred to as “main suction motion”). A main objective of performing the main suction motion is to forcibly discharge ink, an air bubble or the like from the ink ejecting nozzle. In the main suction motion, since the suction pump is operated in the state of closing the atmosphere communication path, it is possible to cause the suction force due to the negative pressure generated in the closed space formed between the head surface of the recording head and the sealing surface of the seal member to act in the ink ejection nozzle. As a result, it is possible to prevent an occurrence of dot missing or the like due to the blockage of the ink ejecting nozzle or the air bubble in the ink ejecting nozzle in advance.
The other of them is a suction motion that seals the head surface of the recording head with the sealing surface of the seal member and operates the suction pump in the state of opening the atmosphere communication path (hereinafter, referred to as “empty suction motion”). A main object of the empty suction motion is to suck the ink stored in the sealing surface of the seal member to deliver the ink to a waste water tank or the like. In the empty suction motion, since the suction pump is operated in the state of opening the atmosphere communication path, a suitable negative pressure is generated in the closed space formed between the head surface of the recording head and the sealing surface of the seal member, and the closed space enters the state in which the atmosphere can enter. As a result, the ink stored in the sealing surface of the seal member is delivered to the waste water tank or the like while being readily sucked by the suction force of the suction pump.
Furthermore, as one of the main functions of the head repairing apparatus, there is a function that wipes out and removes (hereinafter, referred to as “wiping”) ink (liquid) and foreign matters such as a paper powder or dust (hereinafter, referred to as “affixed matter”) which are attached to the head surface of the recording head. Specifically, a member (hereinafter, referred to as “wiper”) formed of a material having elasticity for wiping the affixed matter is provided so as to be displaceable in a direction coming into contact with and separated from the head surface of the recording head. In order to perform the wiping, the wiper is moved to a position capable of coming into slide-contact with the head surface of the recording head in advance. In addition, the recording head is moved in a direction along the head surface of the recording head, thereby bringing the wiper into slide-contact with the head surface of the recording head. As a result, the affixed matter attached to the head surface of the recording head is wiped and removed by the wiper (see JP-A-2007-276304).
The head repairing apparatus has a configuration in which all of the driving of the suction pump, the open and closed of the atmosphere opening valve, the movement of the wiper or the like can be performed by the driving force of one motor. The head repairing apparatus of this configuration has an advantage in that the miniaturization and the low cost of the head repairing apparatus are possible.
However, the head repairing apparatus adopts a configuration in which the opening and closing of the atmosphere opening valve, the movement position of the wiper or the like is selected and maintained by a complicated shaped selection cam in which a plurality of cam surfaces (a non-selection cam surface, a suction cam surface, an empty suction cam surface, and a wiping cam surface) is formed with steps in a rotational axis direction. For this reason, it is possible to perform only a fixed pattern of maintenance operation that performs the wiping after going through the empty suction motion from the main suction motion. That is, for example, it is impossible to perform the maintenance operation by a flexible combination in which the wiping is performed without going through the main suction motion and the empty suction motion or the main suction motion and the empty suction motion are alternately repeated.